Method for preparing transition metal complexes, transition metal complexes prepare using the method, catalyts composition containing the complexes

ABSTRACT

The present invention provides a novel transition metal complex where a monocy-clopentadienyl ligand to which an amido group is introduced is coordinated, a method for synthesizing the complex, and olefin polymerization using the same. The method for preparing a transition metal complex according to the present invention comprises a step of blocking a by-reaction of a nitrogen atom using a compound containing a protecting group, and thus it is possible to prepare a transition metal complex in a simpler manner in a high yield. Further, the transition metal complex according to the present invention has a pentagon ring structure having an amido group connected by a phenylene bridge in which a stable bond is formed in the vicinity of a metal site, and thus, sterically monomers can easily approach the transition metal complex. When a catalyst composition comprising the transition metal complex is applied in copoly-merization of ethylene and monomers having large steric hindrance, a very low density polyolefin copolymer having a density of less than 0.910 g/cc, in addition to a polyolefin having a high molecular weight and a linear low density, can be prepared. Furthermore, the reactivity is also very high.

TECHNICAL FIELD

The present invention relates to a method for preparing a transitionmetal complex, transition metal complex prepared using the method, and acatalyst composition containing the transition metal complex.

This application claims priority benefits from Korean Patent ApplicationNo. 10-2007-003071, filed on Jan. 10, 2007, the entire contents of whichare fully incorporated herein by reference.

BACKGROUND ART

In the early 1990s, Dow Chemical Co. disclosed [Me₂Si(Me₄C₅)NtBu]TiCl₂(Constrained-Geometry Catalyst, hereinafter simply referred to as CGC)(U.S. Pat. No. 5,064,802). CGC shows excellent properties in acopolymerization reaction of ethylene and α-olefin, as compared toconventional metallocene catalysts. Its main two excellent propertiescan be summarized as follows: (1) CGC can be used to form high molecularweight polymers due to its high activity at high polymerizationtemperature, and (2) CGC can be used for copolymerization of α-olefinhaving large steric hindrance, such as 1-hexene and 1-octene. As manyuseful properties of CGC are disclosed, in addition to these propertiesdescribed above, research into synthesis of CGC derivatives as apolymerization catalyst is increasingly conducted in academic andindustrial fields.

As one example of such approaches, synthesis of metal compoundscomprising other various bridges instead of a silicon bridge andcontaining a nitrogen substituent, and polymerization using these metalcompounds were performed. Examples of such metal compounds includeCompounds (1) through (4) (Chem. Rev. 2003, 103, 283).

Compounds (1) through (4) respectively contain a phosphorus bridge (1),an ethylene or propylene bridge (2), a methyllidene bridge (3), and amethylene bridge (4), instead of the silicon bridge of the CGCstructure. However, these compounds could not show enhanced activity,copolymerization performance, or the like when ethylene is polymerizedor when ethylene and α-olefin are copolymerized, as compared to CGC.

In another example of the approaches, a great number of compounds, inwhich an amino ligand in CGC is replaced with an oxido ligand, have beensynthesized. There have been attempts to use such compounds forpolymerization. Examples of such compounds include those represented byFormulae below:

In Compound (5), which was developed by T. J. Marks, et al., acyclopentadiene (Cp) derivative is bridged to an oxido ligand by anortho-phenylene group (Organometallics 1997, 16, 5958). A compoundhaving the same bridge and polymerization using the complex werereported by Mu et al. (Organometallics 2004, 23, 540). A compound inwhich an indenyl ligand is bridged to an oxido ligand by anortho-phenylene group was reported by Rothwell, et al. (Chem. Commun.2003, 1034). In Compound (6), which was reported by Whitby, et al., acyclopentadienyl ligand is bridged to an oxido ligand by three carbonatoms (Organometallics 1999, 18, 348). As reported, Compound (6) showsactivity in syndiotactic polystylene polymerization. Similar compoundswere also reported by Hessen, et al. (Organometallics 1998, 17, 1652).Compound (7), which was reported by Rau, et al., showed activity when itis used for ethylene polymerization and ethylene/1-hexenecopolymerization at a high temperature and a high pressure (210° C., 150Mpa) (J. Organomet. Chem. 2000, 608, 71). Synthesis of Compound (8),which has a similar structure to the compound, and a high-temperatureand high-pressure polymerization using the compound was filed in patentapplication by Sumitomo Co. (U.S. Pat. No. 6,548,686).

However, only some of these catalysts as described above are used incommercial plants. Accordingly, there is a need to develop a catalystexhibiting enhanced polymerization performance, and a method for simplypreparing the catalyst.

DISCLOSURE OF INVENTION Technical Problem

It is a first object of the present invention to provide a method forpreparing a novel transition metal complex.

It is a second object of the present invention to provide a transitionmetal complex prepared using the method.

It is a third object of the present invention to provide a catalystcomposition comprising the transition metal complex.

Technical Solution

According to a first aspect of the present invention, there is provideda method for preparing a novel transition metal complex, comprising thesteps of:

(a) reacting an amine-based compound represented by Formula 1 below withan alkyl lithium, and then adding a compound containing a protectinggroup (-R₀) thereto to prepare a compound represented by Formula 2below;

(b) reacting the compound represented by Formula 2 with an alkyllithium, and adding a ketone-based compound represented by Formula 3below to prepare an amine-based compound represented by Formula 4 below;

(c) reacting the compound represented by Formula 4 with n-butyl lithiumto prepare a dilithium compound represented by Formula 5 below; and

(d) reacting the compound represented by Formula 5 with MCl₄ (M=Ti, Zr,or Hf) and an organic lithium compound to prepare a transition metalcomplex represented by Formula 6 below:

wherein

R₀ is a protecting group;

R₁, R₂, R₃, and R₄ are each independently a hydrogen atom; a silylradical; an alkyl radical having 1 to 20 carbon atoms or an aryl radicalhaving 5 to 20 carbon atoms; an alkenyl radical having 2 to 20 carbonatoms, an alkylaryl radical having 6 to 20 carbon atoms, or an arylalkylradical having 6 to 20 carbon atoms; or a metalloid radical of a metalbelonging to Group 14 substituted with a hydrocarbyl having 1 to 20carbon atoms; at least two of R₁, R₂, R₃, and R₄ may be connected toeach other to form an aliphatic ring having 5 to 20 carbon atoms or anaromatic ring having 5 to 20 carbon atoms; at least two of R₁, R₂, R₃,and R₄ may be connected to each other by an alkylidine radical having 1to 20 carbon atoms, containing an alkyl radical having 1 to 20 carbonatoms or an aryl radical having 5 to 20 carbon atoms to form a ring;

R₅, R₆, R₇, and R₈ are each independently a hydrogen atom; a halogenradical; or an alkyl radical having 1 to 20 carbon atoms or an arylradical having 5 to 20 carbon atoms; and at least two of R₅, R₆, R₇, andR₈ may be connected to each other to form an aliphatic ring having 5 to20 carbon atoms or an aromatic ring having 5 to 20 carbon atoms;

R₉ is a hydrogen atom; a branched, linear, or cyclic alkyl radicalhaving 1 to 20 carbon atoms; or an aryl radical having 5 to 20 carbonatoms; and R₉ and R₈ may be connected to each other to form anN-containing, substituted or unsubstituted, aliphatic ring having 5 to20 carbon atoms or aromatic ring having 5 to 20 carbon atoms;

M is a transition metal belonging to Group 4; and

Q₁ and Q₂ are each independently a halogen radical; an alkylamidoradical having 1 to 20 carbon atoms, or an arylamido radical having 5 to20 carbon atoms; an alkyl radical having 1 to 20 carbon atoms, analkenyl radical having 2 to 20 carbon atoms, an aryl radical having 5 to20 carbon atoms, an alkylaryl radical having 6 to 20 carbon atoms, or anarylalkyl radical having 6 to 20 carbon atoms; or an alkylidene radicalhaving 1 to 20 carbon atoms.

According to one embodiment of the present invention, in the method forpreparing a transition metal complex, as the compound containing aprotecting group, trimethylsilyl chloride, benzyl chloride,t-butoxycarbonyl chloride, benzyloxycarbonyl chloride, carbon dioxide,and the like are preferred.

According to another embodiment of the present invention, in the methodfor preparing a transition metal complex, if the compound containing aprotecting group is carbon dioxide, the compound represented by Formula2 is preferably a lithium carbamate compound represented by Formula 2abelow:

wherein R₅, R₆, R₇, R₈, R₉, and R₁₀ are as defined above.

According to a still another embodiment of the present invention, in themethod for preparing a transition metal complex, the transition metalcomplex represented by Formula 6 is preferably represented by Formula 7,Formula 8, or Formula 9, as shown below:

wherein

R₁₁, R₁₂, R₁₃, and R₁₄ are each independently a hydrogen atom; an alkylradical having 1 to 20 carbon atoms or an aryl radical having 5 to 20carbon atoms; an alkenyl radical having 2 to 20 carbon atoms, analkylaryl radical having 6 to 20 carbon atoms, or an arylalkyl radicalhaving 6 to 20 carbon atoms; or a metalloid radical of a metal belongingto Group 14 substituted with hydrocarbyl having 1 to 20 carbon atoms;and at least two of R₁₁, R₁₂, R₁₃, and R₁₄ may be connected to eachother to form an aliphatic ring having 5 to 20 carbon atoms or anaromatic ring having 5 to 20 carbon atoms;

R₁₅, R₁₆, R₁₇, R₁₈, R₁₉ , and R₂₀ are each independently a hydrogenatom; a halogen radical; an alkyl radical having 1 to 20 carbon atoms oran aryl radical having 5 to 20 carbon atoms; and at least two of R₁₅,R₁₆, R₁₇, R₁₈, R₁₉, and R₂₀ may be connected to each other to form analiphatic ring having 5 to 20 carbon atoms or an aromatic ring having 5to 20 carbon atoms;

R₂₁ is a hydrogen atom; a branched, linear, or cyclic alkyl radicalhaving 1 to 20 carbon atoms; or an aryl radical having 5 to 20 carbonatoms;

M is a transition metal belonging to Group 4; and

Q₃ and Q₄ are each independently a halogen radical; an alkylamidoradical having 1 to 20 carbon atoms or an arylamido radical having 5 to20 carbon atoms; or an alkyl radical having 1 to 20 carbon atoms.

According to a still another embodiment of the present invention, in themethod for preparing a transition metal complex, the transition metalcomplex represented by Formula 6 is preferably represented by one of thestructural formulae as shown below:

According to a second aspect of the present invention, there is provideda transition metal complex represented by Formula 6 below:

wherein

R₁, R₂, R₃, and R₄ are each independently a hydrogen atom; a silylradical; an alkyl radical having 1 to 20 carbon atoms or an aryl radicalhaving 5 to 20 carbon atoms; an alkenyl radical having 2 to 20 carbonatoms, an alkylaryl radical having 6 to 20 carbon atoms, or an arylalkylradical having 6 to 20 carbon atoms; or a metalloid radical of a metalbelonging to Group 14 substituted with hydrocarbyl having 1 to 20 carbonatoms; at least two of R₁, R₂, R₃, and R₄ may be connected to each otherto form an aliphatic ring having 5 to 20 carbon atoms or an aromaticring having 5 to 20 carbon atoms; and at least two of R₁, R₂, R₃, and R₄may be connected to each other by an alkylidine radical having 1 to 20carbon atoms, containing an alkyl radical having 1 to 20 carbon atoms oran aryl radical having 5 to 20 carbon atoms to form a ring;

R₅, R₆, R₇, and R₈ are each independently a hydrogen atom; a halogenradical; an alkyl radical having 1 to 20 carbon atoms or an aryl radicalhaving 5 to 20 carbon atoms; and at least two of R₅, R₆, R₇, and R₈ maybe connected to each other to form an aliphatic ring having 5 to 20carbon atoms or an aromatic ring having 5 to 20 carbon atoms;

R₉ is a hydrogen atom; a branched, linear, or cyclic alkyl radicalhaving 1 to 20 carbon atoms; or an aryl radical having 5 to 20 carbonatoms; R₉ and R₈ may be connected to each other to form an N-containing,substituted or unsubstituted, aliphatic ring having 5 to 20 carbon atomsor aromatic ring having 5 to 20 carbon atoms;

M is a transition metal belonging to Group 4; and

Q₁ and Q₂ are each independently a halogen radical; an alkylamidoradical having 1 to 20 carbon atoms, or an arylamido radical having 5 to20 carbon atoms; an alkyl radical having 1 to 20 carbon atoms, analkenyl radical having 2 to 20 carbon atoms, an aryl radical having 5 to20 carbon atoms, an alkylaryl radical having 6 to 20 carbon atoms, or anarylalkyl radical having 6 to 20 carbon atoms; or an alkylidene radicalhaving 1 to 20 carbon atoms.

According to one embodiment of the present invention, the transitionmetal complex represented by Formula 6 is preferably represented by oneof Formulae 7, 8, and 9 below:

wherein

R₁₁, R₁₂, R₁₃, and R₁₄ are each independently a hydrogen atom; a silylradical; an alkyl radical having 1 to 20 carbon atoms or an aryl radicalhaving 5 to 20 carbon atoms; an alkenyl radical having 2 to 20 carbonatoms, an alkylaryl radical having 6 to 20 carbon atoms, or an arylalkylradical having 6 to 20 carbon atoms; or a metalloid radical of a metalbelonging to Group 14 substituted with hydrocarbyl having 1 to 20 carbonatoms; and at least two of R₁₁, R₁₂, R₁₃, and R₁₄ may be connected toeach other to form an aliphatic ring having 5 to 20 carbon atoms or anaromatic ring having 5 to 20 carbon atoms;

R₁₅, R₁₆, R₁₇, R₁₈, R₁₉, and R₂₀ are each independently a hydrogen atom;a halogen radical; an alkyl radical having 1 to 20 carbon atoms or anaryl radical having 5 to 20 carbon atoms; and at least two of R₁₅, R₁₆,R₁₇, R₁₈, R₁₉, and R₂₀ may be connected to each other to form analiphatic ring having 5 to 20 carbon atoms or an aromatic ring having 5to 20 carbon atoms;

R₂₁ is a hydrogen atom; a branched, linear, or cyclic alkyl radicalhaving 1 to 20 carbon atoms; or an aryl radical having 5 to 20 carbonatoms;

Q₃ and Q₄ are each independently a halogen radical; an alkylamidoradical having 1 to 20 carbon atoms or an arylamido radical having 5 to20 carbon atoms; or an alkyl radical having 1 to 20 carbon atoms; and

M is a transition metal belonging to Group 4.

According to another embodiment of the present invention, the transitionmetal complex represented by Formula 6 is represented by one of thestructural formulae as shown below:

Furthermore, according to the second aspect of the present invention,there is provided an amine-based compound represented by Formula 4below:

wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, and R₉ are as defined above.

According to a third aspect of the present invention, there is provideda catalyst composition comprising:

a transition metal complex represented by Formula 6 below; and

at least one cocatalyst compound selected from the group consisting ofthe compounds represented by Formulae 10, 11, and 12 below:

wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, Q₁, and Q₂ are as definedabove.

—[Al(R₂₂)—O]_(a)—  <Formula 10>

wherein R₂₂'s are each independently a halogen radical; a hydrocarbylradical having 1 to 20 carbon atoms; or a hydrocarbyl radical having 1to 20 carbon atoms substituted with halogen; and a is an integer of noless than 2;

D(R₂₂)₃  <Formula 11>

wherein D is aluminum or boron; and R₂₂'s are each independently asdefined above;

[L-H]⁺[Z(A)₄]⁻ or [L]⁺[Z(A)₄]⁻  <Formula 12>

wherein L is a neutral or cationic Lewis acid; H is a hydrogen atom; Zis an element belonging to Group 13; A's are each independently an arylradial having 6 to 20 carbon atoms or alkyl radical having 1 to 20carbon atoms, substituted with one or more hydrogen atoms; and thesubstituent is a halogen, a hydrocarbyl radical having 1 to 20 carbonatoms, an alkoxy radical having 1 to 20 carbon atoms, or an aryloxyradical having 6 to 20 carbon atoms.

According to one embodiment of the present invention, in the catalystcomposition, the transition metal complex represented by Formula 6 ispreferably represented by Formula 7, Formula 8, or Formula 9, as shownbelow:

wherein R₁₁, R₁₂, R₁₃, R₁₄, R₁₅, R₁₆, R₁₇, R₁₈, R₁₉, R₂₀, R₂₁, Q₃, andQ₄ are as defined above.

According to another embodiment of the present invention, in thecatalyst composition, the transition metal complex represented byFormula 6 is preferably represented by one of the structural formulae asshown below:

According to another embodiment of the present invention, in thecatalyst composition, the molar ratio of the transition metal complexrepresented by Formula 6 to the compound represented by Formula 10 or 11is preferably 1:2 to 1:5000, and the molar ratio of the transition metalcomplex represented by Formula 6 to the compound represented by Formula12 is preferably 1:1 to 1:25.

As compared with a conventional method for preparing a transition metalcomplex using boronic acid, etc., the method for preparing a transitionmetal complex according to the present invention comprises a step ofblocking a by-reaction of a nitrogen atom using a compound containing aprotecting group, and thus it is possible to prepare a transition metalcomplex in a simpler manner in a high yield.

Advantageous Effects

The method for preparing a transition metal complex according to thepresent invention comprises a step of blocking a by-reaction of anitrogen atom using a compound containing a protecting group, and thusit is possible to prepare a transition metal complex in a simpler mannerin a high yield.

Furthermore, the transition metal complex according to the presentinvention has a pentagon ring structure having an amido group connectedby a phenylene bridge in which a stable bond is formed in the vicinityof a metal site, and thus, sterically monomers can easily approach thetransition metal complex.

When a catalyst composition comprising the transition metal complex isapplied in copolymerization of ethylene and monomers having large sterichindrance, a very low density polyolefin copolymer having a density ofless than 0.910 g/cc, in addition to a polyolefin having a highmolecular weight and a linear low density, can be prepared. Furthermore,the reactivity is also very high.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

According to a first aspect of the present invention, the inventionprovides a method for preparing a transition metal complex, comprisingthe steps of:

(a) reacting an amine-based compound represented by Formula 1 below withan alkyl lithium, and then adding a compound containing a protectinggroup (-R₀) thereto to prepare a compound represented by Formula 2below;

(b) reacting the compound represented by Formula 2 with an alkyllithium, and adding a ketone-based compound represented by Formula 3below to prepare an amine-based compound represented by Formula 4 below;

(c) reacting the compound represented by Formula 4 with n-butyl lithiumto prepare a dilithium compound represented by Formula 5 below; and

(d) reacting the compound represented by Formula 5 with MCl₄ (M=Ti, Zr,or Hf) and an organic lithium compound to prepare a transition metalcomplex represented by Formula 6 below:

wherein R₀, R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, M, Q₁ and Q₂ are asdefined above.

In the method for preparing a transition metal complex, a protectinggroup for a nitrogen atom is introduced to the amine compoundrepresented by Formula 1, and then a cyclocyclopentadienyl group isintroduced. Thereafter, the protecting group introduced to the nitrogenatom is removed, thereby preparing a transition metal complex.

As the compound containing a protecting group, trimethylsilyl chloride,benzyl chloride, t-butoxycarbonyl chloride, benzyloxycarbonyl chloride,carbon dioxide, and the like are preferred.

Thus, as the protecting group, a trimethylsilyl group, a benzyl group, at-butoxycarbonyl group, a benzyloxycarbonyl group, —C(═O)O⁻, and thelike are preferred.

Particularly, if the compound containing a protecting group is carbondioxide, the compound represented by Formula 2 is a lithium carbamatecompound represented by Formula 2a below:

wherein R₅, R₆, R₇, R₈, R₉, and R₁₀ are as defined above.

Carbon dioxide can be easily removed from the lithium carbamate compoundby controlling the temperature. Accordingly, in the preparation methodin which carbon dioxide is introduced for the preparation of thetransition metal complex represented by Formula 1, a transition metalcomplex can be prepared in a simple and efficient manner in a high yieldwithout any by-reaction of a nitrogen atom present in the reactants.

In the method for preparing a transition metal complex, the transitionmetal complex represented by Formula 6 is preferably represented byFormula 7, Formula 8, or Formula 9, as shown below:

wherein R₁₁, R₁₂, R₁₃, R₁₄, R₁₅, R₁₆, R₁₇, R₁₈, R₁₉, R₂₀, R₂₁, M, Q₃,and Q₄ are as defined above.

Furthermore, in the method for preparing a transition metal complex, thetransition metal complex represented by Formula 6 is more preferablyrepresented by one of the structural formulae as shown below:

One embodiment of the specific method for preparing the compound asabove can be shown in Reaction Schemes 1 and 2 below:

In Reaction Scheme 1, R16 and R20 are each preferably hydrogen, methyl,or the like, Cp′ is preferably tetramethylcyclopentanone, indenone,fluorenone, or the like, Cp″ is preferably tetramethylcyclopentadienyl,indenyl, fluorenyl, or the like, and n is 0 or 1.

In Reaction Scheme 2, R3 is preferably ethyl, isopropyl, or the like,Cp′ is tetramethylcyclopentanone, indenone, fluorenone, or the like, andCp″ is tetramethylcyclopentadienyl, indenyl, fluorenyl, or the like.

Details on Reaction Schemes as above are provided in Examples.

According to a second aspect of the present invention, the inventionprovides a transition metal complex represented by Formula 6 below:

wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, M, Q₁, and Q₂ are as definedabove.

A metal site of the transition metal complex represented by Formula 6 isconnected by a cyclopentadienyl ligand which is connected to a phenylenebridge to which a ring shaped amido group is introduced. Thus, itsstructural inherence gives characteristics that the angle of Cp-M-Nstructure is narrow, and a wide angle is maintained in the Q₁-M-Q₂structure to which a monomer approaches. In addition, as compared to aCGC structure that includes a silicon bridge for connection, thetransition metal complex represented by Formula 6 has a structure inwhich Cp, a phenylene bridge, nitrogen, and a metal site are connectedin this order to form a stable and strong pentagon ring. Accordingly,when the complex compound which is activated by the reaction with acocatalyst such as methylaluminoxane and B(C₆F₅)₃, is then applied inolefin polymerization, a polyolefin which is characterized by a highactivity, a high molecular weight, a high degree of copolymerization,and the like, can be obtained even at a high polymerization temperature.In particular, a very low density polyolefin copolymer having a densityof less than 0.910 g/cc, in addition to a linear, low densitypolyethylene having a density of about 0.910 to 0.930 g/cc, can also beprepared since the structure of the catalyst allows a great amount ofα-olefin to be introduced. Various substituents can be introduced into acyclopentadienyl ring and a quinoline-based ring. As a consequence, thestructures, properties, etc. of the resulting polyolefin can becontrolled since electronic and steric environments in the vicinity ofthe metal can be easily regulated. The complex according to the presentinvention may be preferably used to prepare a catalyst forpolymerization of olefin monomers. However, use of the complex is notlimited thereto, and the complex can be applied in any other field wherethe transition metal complex can be used

Specifically, as the transition metal complex represented by Formula 6,preferred is a transition metal complex having a structure representedby Formula 7, 8, or 9 below, which can control electronic and stericenvironments in the vicinity of metal:

wherein R₁₁, R₁₂, R₁₃, R₁₄, R₁₅, R₁₆, R₁₇, R₁₈, R₁₉, R₂₀, R₂₁, M, Q₃,and Q₄ are as defined above.

Furthermore, as the transition metal complex represented by Formula 6,further preferred is a complex represented by one of the structuralformulae below:

Moreover, according to the second aspect of the present invention, theinvention provides an amine-based compound represented by Formula 4below:

wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, and R₉ are as defined above.

The amine-based compound represented by Formula 4 is an intermediateobtained during the preparation of the transition metal complex of thepresent invention, which can also be used in other fields.

According to a third aspect of the present invention, the inventionprovides a catalyst composition comprising:

a transition metal complex represented by Formula 6 below; and

at least one cocatalyst compound selected from the group consisting ofthe compounds represented by Formulae 10, 11, and 12 below:

wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, Q₁, and Q₂ are as definedabove.

—[Al(R₂₂)—O]_(a)—  <Formula 10>

wherein R₂₂'s are each independently a halogen radical; a hydrocarbylradical having 1 to 20 carbon atoms; or a hydrocarbyl radical having 1to 20 carbon atoms substituted with halogen; and a is an integer of noless than 2;

D(R₂₂)₃  <Formula 11>

wherein D is aluminum or boron; and R₂₂'s are each independently asdefined above;

[L-H]⁺[Z(A)₄]- or [L]⁺[Z(A)₄]⁻  <Formula 12>

wherein L is a neutral or cationic Lewis acid; H is a hydrogen atom; Zis an element belonging to Group 13; A's are each independently an arylradial having 6 to 20 carbon atoms or alkyl radical having 1 to 20carbon atoms, substituted with one or more hydrogen atoms; and thesubstituent is a halogen, a hydrocarbyl radical having 1 to 20 carbonatoms, an alkoxy radical having 1 to 20 carbon atoms, or an aryloxyradical having 6 to 20 carbon atoms.

The catalyst composition of the present invention can be used in variousolefin polymerizations.

In the catalyst composition, the transition metal complex represented byFormula 6 is preferably represented by Formula 7, Formula 8, or Formula9, as shown below:

wherein R₁₁, R₁₂, R₁₃, R₁₄, R₁₅, R₁₆, R₁₇, R₁₈, R₁₉, R₂₀, R₂₁, Q₃, andQ₄ are as defined above.

More specifically, in the catalyst composition, the transition metalcomplex represented by Formula 6 is preferably represented by one of thestructural formulae as shown below:

Moreover, the present invention provides a method for preparing thecatalyst composition, comprising the steps of:

bringing the transition metal complex represented by Formula 6 intocontact with a compound represented by Formula 10 or 11 to obtain amixture; and adding a compound represented by Formula 12 to the mixture.

The present invention further provides a method for preparing thecatalyst composition, comprising the steps of:

bringing the transition metal complex represented by Formula 6 intocontact with a compound represented by Formula 12.

In the former method for preparing the catalyst composition, the molarratio of the transition metal complex represented by Formula 6 to thecompound represented by Formula 10 or 11 is preferably 1:2 to 1:5000,more preferably 1:10 to 1:1,000, and most preferably 1:20 to 1:500.

Meanwhile, the molar ratio of the transition metal complex representedby Formula 6 to the compound represented by Formula 12 is preferably 1:1to 1:25, more preferably 1:1 to 1:10, and most preferably 1:1 to 1:5.

When the molar ratio of the transition metal complex represented byFormula 6 to the compound represented by Formula 10 or 11 is less than1:2, the metal compound is insufficiently alkylated since the amount ofan alkylating agent is too small. On the other hand, when the molarratio of the transition metal complex represented by Formula 6 to thecompound represented by Formula 10 or 11 is greater than 1:5,000, themetal compound is alkylated, but the remaining excess alkylating agentcan react with the activator of Formula 12 so that the alkylated metalcompound is less activated. When the molar ratio of the transition metalcomplex to the compound represented by Formula 12 is less than 1:1, theamount of the activator is relatively small so that the metal compoundis less activated . On the other hand, when the molar ratio of thetransition metal complex to the compound represented by Formula 12 isgreater than 1:25, the metal compound is completely activated but excessactivator remains, thus leading to problems that the preparation processfor the catalyst composition is expensive, and the purity of theresulting polymer is poor.

In the latter method for preparing the catalyst composition, the molarratio of the transition metal complex represented by Formula 6 to thecompound represented by Formula 12 is preferably 1:10 to 1:10,000, morepreferably 1:100 to 1:5,000, and most preferably 1:500 to 1:2,000. Whenthe molar ratio of the transition metal complex represented by Formula 6to the compound represented by Formula 12 is less than 1:10, the metalcompound is insufficiently alkylated since the amount of an alkylatingagent is relatively small, thus leading to problems that the activity ofthe catalyst composition is deteriorated. On the other hand, when themolar ratio of the transition metal complex represented by Formula 6 tothe compound represented by Formula 12 is greater than 1:10,000, themetal compound is completely activated but excess activator remains,thus leading to problems that the preparation process for the catalystcomposition is expensive, and the purity of the resulting polymer ispoor.

A reaction solvent used in the preparation of the activated compositionmay be a hydrocarbon solvent such as pentane, hexane, and heptane, or anaromatic solvent such as benzene and toluene, but is not limitedthereto, and any solvent that is available in the art can be used.

In addition, the transition metal complex represented by Formula 6 andthe cocatalyst may be used as loaded on silica or alumina.

The compound represented by Formula 10 is not particularly limited aslong as it is an alkylaluminoxane, and it is more preferablymethylaluminoxane, ethylaluminoxane, isobutylaluminoxane,butylaluminoxane, or the like, and most preferably methylaluminoxane.

The compound represented by Formula 11 is not particularly limited, butpreferable examples thereof include trimethylaluminum, triethylaluminuntriisobutylaluminum, tripropylaluminum, tributylaluminum,dimethylchloroaluminum, triisopropylaluminum tri-s-butylaluminum,tricyclopentylaluminum, tripentylaluminum triisopentylaluminum,trihexylaluminum trioctylaluminum, ethyldimethylaluminum,methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum,dimethylaluminum-methoxide, dimethylaluminumethoxide, trimethylboron,triethylboron, triisobutylboron, dripropylboron, and tributylboron. Morepreferably, the compound is selected frcm trimethylaluminum,triethylaluminum, and triisobutylaluminum.

Examples of the compound represented by Formula 12 may includetriethylammoniumtetraphenylboron, tributylammoniumtetraphenylboron,trimethylammoniumtetraphenylboron, tripropylammoniumtetraphenylboron,trimethylammoniumtetra(p-tolyl)boron,trimethylammoniumtetra(o,p-dimethylphenyl)boron,tributylammoniumtetra(p-trifluoromethylphenyl)boron,trimethylammoniumtetra(p-trifluoromethylphenyl)boron,tributylammoniumtetrapentafluorophenylboron,N,N-diethylaniliniumtetraphenylboron,N,N-diethylaniliniumtetraphenylboron,N,N-diethylaniliniumtetrapentafluorophenylboron,diethylammoniumtetrapentafluorophenylboron,triphenylphosphoniumtetraphenylboron,trimethylphosphoniumtetraphenylboron,triethylammoniumtetraphenylaluminum,tributylammoniumtetraphenylaluminum,trimethylammoniumtetraphenylaluminum,tripropylammoniumtetraphenylaluminum,trimethylammoniumtetra(p-tolyl)aluminum,tripropylammoniumtetra(p-tolyl)aluminum,triethylammoniumtetra(o,p-dimethylphenyl)aluminum,tributylammoniumtetra(p-trifluoromethylphenyl)aluminum,trimethylammoniumtetra(p-trifluoromethylphenyl)aluminum,tributylammoniumtetrapentafluorophenylaluminum,N,N-diethylaniliniumtetraphenylaluminum,N,N-diethylaniliniumtetraphenylaluminum,N,N-diethylaniliniumtetrapentafluorophenylaluminum,diethylammoniumtetrapentatetraphenylaluminum,triphenylphosphoniumtetraphenylaluminum,trimethylphosphoniumtetraphenylaluminum,triethylammoniumtetraphenylaluminum,tributylammoniumtetraphenylaluminum, trimethylammoniumtetraphenylboron,tripropylammoniumtetraphenylboron, trimethylammoniumtetra(p-tolyl)boron,tripropylammoniumtetra(p-tolyl)boron,triethylammoniumtetra(o,p-dimethylphenyl)boron,trimethylammoniumtetra(o,p-dimethylphenyl)boron,tributylammoniumtetra(p-trifluoromethylphenyl)boron,trimethylammoniumtetra(p-trifluoromethylphenyl)boron,tributylammoniumtetrapentafluorophenylboron,N,N-diethylaniliniumtetraphenylboron,N,N-diethylaniliniumtetraphenylboron,N,N-diethylaniliniumtetrapentafluorophenylboron,diethylammoniumtetrapentafluorophenylboron,triphenylphosphoniumtetraphenylboron,triphenylcarboniumtetra(p-trifluoromethylphenyl)boron, andtriphenylcarboniumtetrapentafluorophenylboron.

It is possible that the catalyst composition comprising the transitionmetal complex represented by Formula 6, and at least one compoundselected from the group consisting of the compounds represented byFormulae 10 to 12 is brought into contact with at least one olefinmonomer to prepare a polyolefin homopolymer or copolymer.

A most preferable preparation process using the activated catalystcomposition is a solution process, but when the composition is usedtogether with an inorganic support such as silica, it can also beapplied in a slurry or gas phase process.

In the preparation process, the activated catalyst composition may bedissolved or diluted in a solvent suitable for olefin polymerization,before being incorporated. Examples of the solvent include a C₅₋₁₂aliphatic hydrocarbon solvent such as pentane, hexane, heptane, nonane,decane, and isomers thereof; an aromatic hydrocarbon solvent such astoluene and benzene; and a hydrocarbon solvent substituted with achlorine atom such as dichloromethane and chlorobenzene. The solventused may be treated with a small amount of alkylaluminum to eliminate asmall amount of water, air, and the like which poison the catalystcomposition, or a cocatalyst can further be used to perform the process.

Examples of the olefin-based monomer which can be polymerized using themetal compounds and the cocatalysts include ethylene, an α-olefin, and acyclic olefin. A diene olefin-based monomer or a triene olefin-basedmonomer which have at least two double bonds can also be polymerized.Examples of such the monomers include ethylene, propylene, 1-butene,1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene,1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene,norbornene, norbornadiene, ethylidene norbornene, phenylnorbornene,vinyl norbornene, dicyclopentadiene, 1,4-butadiene, 1,5-pentadiene,1,6-hexadiene, styrene, α-methylstyrene, divinylbenzene, and3-chloromethyl styrene. At least two kinds of the monomers may be mixed,and copolymerized.

In particular, in the preparation method according to the presentinvention, the catalyst composition is characterized in that it can beused to copolymerize monomers having large steric hindrance such asethylene and 1-octene even at a high reaction temperature of 90° C. orhigher, thereby obtaining a copolymer having a high molecular weight anda very low density of less than 0.910 g/cc.

In the present specification, the “N-containing, substituted orunsubstituted, aliphatic ring having 5 to 20 carbon atoms or aromaticring having 5 to 20 carbon atoms” is preferably has a substituent suchas a hydrogen atom; a silyl radical; an alkyl radical having 1 to 20carbon atoms, or an aryl radical having 5 to 20 carbon atoms.

Further, in the present specification, the “silyl radical” is preferablytrimethylsilyl or triethylsilyl.

MODE FOR THE INVENTION

Hereinbelow, the present invention will be described in greater detailwith reference to the following Examples. Examples are for illustrativepurposes only, and are not intended to limit the scope of the presentinvention.

Synthesis of Ligands and Transition Metal Complexes

Organic reagents and solvents were purchased from Aldrich Co., Inc. andMerck Co., Inc., purified using a standard method, and then used. Eachstep for synthesis was performed while isolated from air and moisture toimprove reproducibility of experiments. In order to demonstrate thestructure of compounds, a 400 MHz nuclear magnetic resonance (NMR) andan X-ray spectrometer were used to obtain spectra and diagrams,respectively.

EXAMPLE 1 Preparation of8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline(Compound 3a)

1,2,3,4-tetrahydroquinoline (13.08 g, 98.24 mmol) and diethylether (150mL) were put into a Schlenk flask. The Schlenk flask was immersed in adry ice/acetone cooling bath at −78° C., and shaken for 30 minutes.Then, n-BuLi (n-butyl lithium, 39.3 mL, 2.5 M, 98.24 mmol) wasintroduced thereto using a syringe under nitrogen atmosphere to form apale yellow slurry. Thereafter, the flask was shaken for 2 hours, andthen the flask was warmed to ambient temperature while removing theresulting butane gas. The flask was again immersing into the coolingbath at −78° C., and then a CO₂ gas was introduced thereto. Asintroducing carbon dioxide gas, the slurry gradually disappeared to forma clear solution. The flask was connected into a bubbler to remove thecarbon dioxide gas, while raising the temperature to ambienttemperature. Thereafter, excess CO₂ gas and the solvent were removedunder vacuum. The flask was transferred into a dry box, and then pentanewas added thereto. The mixture was thoroughly stirred, and then filteredto obtain lithium carbamate (Compound 2a) as white solid compound, wherediethylether was coordinated. Here, the yield was 100%.

¹H NMR (C6D6, C5D5N): δ 1.90 (t, J=7.2 Hz, 6H, ether), 1.50 (br s, 2H,quin-CH₂), 2.34 (br s, 2H, quin-CH₂), 3.25 (q, J=7.2 Hz, 4H, ether),3.87 (br, s, 2H, quin-CH₂), 6.76 (br d, J=5.6 Hz, 1H, quin-CH) ppm, ¹³CNMR (C6D6): δ 24.24, 28.54, 45.37, 65.95, 121.17, 125.34, 125.57,142.04, 163.09 (C═O) ppm.

The resulting lithium carbamate compound (Compound 2a) (8.47 g, 42.60mmol) was put into a Schlenk flask. Thereafter, tetrahydrofuran (4.6 g,63.9 mmol) and diethylether (45 mL) were added thereto in this order.The Schlenk flask was immersed in an acetone/small amount of dry icecooling bath at −20° C., and shaken for 30 minutes, and then tert-BuLi(25.1 mL, 1.7 M, 42.60 mmol) was added thereto. At that time, thereaction mixture turned red. While maintaining the temperature at −20°C., the reaction mixture was stirred for 6 hours. A CeCl₃.2LiCl solutionof tetrahydrofuran (129 mL, 0.33 M, 42.60 mmol) andtetramethylcyclopentanone (5.89 g, 42.60 mmol) were mixed in a syringe,and then introduced into the flask under nitrogen atmosphere. The flaskwas gradually warmed to ambient temperature, and one hour later, theincubator was removed, and the temperature was maintained at ambienttemperature. Then, water (15 mL) was added into the flask, and ethylacetate was added thereto to obtain a filtrate. The filtrate wastransferred into a seperatory funnel, and hydrochloric acid (2 N, 80 mL)was added thereto, and the seperatory funnel was shaken for 12 minutes.Thereafter, a saturated, aqueous sodium carbonate solution (160 mL) wasadded thereto to neutralize the solution, and then an organic phase wasextracted. To this organic phase, anhydrous magnesium sulfate was addedto remove moisture, the resultant was filtered and taken, and thesolvent was removed. The resulting filtrate was purified by columnchromatography using a hexane/ethyl acetate (v/v, 10:1) solvent toobtain a yellow oil. The yield was 40%.

¹H NMR (C6D6): δ 1.00 (br d, 3H, Cp-CH₃), 1.63-1.73 (m, 2H, quin-CH₂),1.80 (s, 3H, Cp-CH₃), 1.81 (s, 3H, Cp-CH₃), 1.85 (s, 3H, Cp-CH₃), 2.64(t, J=60 Hz, 2H, quin-CH₂), 2.84-2.90 (br, 2H, quin-CH₂), 3.06 (br s,1H, Cp-H), 3.76 (br s, 1H, N—H), 6.77 (t, J=7.2 Hz, 1H, quin-CH), 6.92(d, J=2.4 Hz, 1H, quin-CH), 6.94 (d, J=2.4 Hz, 1H, quin-CH) ppm.

EXAMPLE 2 Preparation of[(1,2,3,4-tetrahydroquinolin-8-yl)tetramethylcyclopentadienyl-eta5,kapa-N]titaniumdimethyl (Compound 5a)

In a dry box, the compound 3a (8.07 g, 32.0 mmol) as prepared in Example1 and diethylether (140 mL) were put into a round flask, and cooled to−30° C. n-BuLi (17.7 g, 2.5 M, 64.0 mmol) was slowly added thereto understirring. While raising the temperature to ambient temperature, reactionwas performed for 6 hours. Thereafter, the mixture was washed withdiethylether several times, and filtered to obtain a solid. Theremaining solvent was removed under vacuum to obtain a dilithiumcompound (Compound 4a) (9.83 g) as a yellow solid. The yield was 95%.

¹H NMR (C6D6, C5D5N): δ 2.38 (br s, 2H, quin-CH₂), 2.53 (br s, 12H,Cp-CH₃), 3.48 (br s, 2H, quin-CH₂), 4.19 (br s, 2H, quin-CH₂), 6.77 (t,J=6.8 Hz, 2H, quin-CH), 7.28 (br s, 1H, quin-CH), 7.75 (br s, 1H,quin-CH) ppm.

In a dry box, TiCl₄.DME (4.41 g, 15.76 mmol) and diethylether (150 mL)were put into a round flask, and while stirring the mixture at −30° C.,MeLi (21.7 mL, 31.52 mmol, 1.4 M) was slowly added thereto. Afterstirring the mixture for 15 minutes, the resulting[(1,2,3,4-tetrahydroquinolin-8-yl)tetramethylcyclopentadienyl-eta5,kapa-N]dilithiumcompound (Compound 4a) (5.30 g, 15.76 mmol) was put into the flask.While raising the temperature to ambient temperature, the mixture wasstirred for 3 hours. After completion of the reaction, the solvent wasremoved under vacuum dissolved in pentane, and then filtered to obtain afiltrate. The pentane was removed under vacuum to obtain a dart browncompound (3.70 g). The yield was 71.3%.

¹H NMR (C6D6): δ 0.59 (s, 6H, Ti—CH₃), 1.66 (s, 6H, Cp-CH₃), 1.69 (br t,J=6.4 Hz, 2H, quin-CH₂), 2.05 (s, 6H, Cp-CH₃), 2.47 (t, J=6.0 Hz, 2H,quin-CH₂), 4.53 (m, 2H, quin-CH₂), 6.84 (t, J=7.2 Hz, 1H, quin-CH), 6.93(d, J=7.6 Hz, quin-CH), 7.01 (d, J=6.8 Hz, quin-CH) ppm. ¹³C NMR (C6D6):δ 12.12, 23.08, 27.30, 48.84, 51.01, 119.70, 119.96, 120.95, 12699,128.73, 131.67, 136.21 ppm.

EXAMPLE 3 Preparation of 5-indenyl-1,2,3,4-tetrahydroquinoline (Compound3b)

The procedure was carried out in the same manner as the preparationmethod of [Example 1] except that indenone was used instead oftetramethylcyclopentanone, and the resultant was purified by columnchromatography using a hexane:ethyl acetate (v/v, 20:1) solvent toobtain a yellow oil. The yield was 49%.

¹H NMR (C6D6): δ 1.58-1.64 (m, 2H, quin-CH₂), 2.63 (t, J=6.8 Hz, 2H,quin-CH₂), 2.72-2.77 (m, 2H, quin-CH₂), 3.17 (d, J=2.4 Hz, 2H,indenyl-CH₂), 3.85 (br s, 1H, N—H), 6.35 (t, J=2.0 Hz, 1H, indenyl-CH),6.76 (t, J=7.6 Hz, 1H, quin-CH), 6.98 (d, J=7.2 Hz, 1H, quin-CH), 7.17(td, J=1.6, 7.2 Hz, 1H, quin-CH), 7.20 (td, J=1.6, 7.2 Hz, 2H,indenyl-CH), 7.34 (d, J=7.2 Hz, 1H, indenyl-CH), 7.45 (dd, J=1.2, 6.8Hz, 1H, indenyl-CH) ppm. ¹³C NMR (C6D6): δ 12.12, 23.08, 27.30, 48.84,51.01, 119.70, 119.96, 120.95, 126.99, 128.73, 131.67, 136.21 ppm.

EXAMPLE 4 Preparation of[(1,2,3,4-tetrahydroquinolin-8-yl)indenyl-eta5,kapa-N]titanium dimethyl(Compound 5b)

A dilithium compound (Compound 4b) was prepared in the same manner asthe preparation method of [Example 2] except that5-indenyl-1,2,3,4-tetrahydroquinoline was used instead of8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline.The yield was 95%.

¹H NMR (C6D6): δ 2.02 (t, J=4.8 Hz, 2H, quin-CH₂), 3.15 (t, J=5.6 Hz,2H, quin-CH₂), 3.94 (br s, 2H, quin-CH₂), 6.31 (t, J=7.2 Hz, 1H,indenyl-CH), 6.76-6.83 (m, 2H, quin-CH), 6.99 (t, J=7.2, 2.0 Hz, 2H,quin-CH), 7.48 (d, J=7.2 Hz, 2H, indenyl-CH), 8.02 (t, J=8.0 Hz, 2H,indenyl-CH) ppm.

A titanium compound (Compound 5b) was prepared in the same manner as in[Example 2] using the resulting lithium salt compound (Compound 4b). Theyield was 47%.

¹H NMR (C6D6): δ −0.01 (s, 3H, Ti—CH₃), 0.85 (s, 3H, Ti—CH₃), 1.56-1.68(m, 2H, quin-CH₂), 2.43 (t, J=6.4 Hz, 2H, quin-CH₂), 6.30 (d, J=3.6 Hz,1H, indenyl-CH), 6.61 (d, J=3.6 Hz, 1H, indenyl-CH), 6.70 (ddd, J=0.8,6.8, 8.4 Hz, 1H, indenyl-CH), 6.85 (t, J=7.6 Hz, 1H, quin-CH), 6.95 (tt,J=0.8, 6.8 Hz, 1H, quin-CH), 7.01 (tdd, J=0.8, 6.8, 8.4 Hz, 2H,indenyl-CH), 7.13-7.17 (m, 1H, quin-CH), 7.48 (d, J=8.4 Hz, 1H,indenyl-CH) ppm. ¹³C NMR (C6D6): δ 22.83, 27.16, 49.35, 55.12, 58.75,103.36, 119.63, 120.30, 123.18, 125.26, 125.60, 127.18, 127.36, 127.83,129.13, 129.56, 135.10, 161.74 ppm.

EXAMPLE 5 Preparation of 5-fluorenyl-1,2,3,4-tetrahydroquinoline(Compound 3c)

The procedure was carried out in the same manner as the preparationmethod of [Example 1] except that fluorenone was used instead oftetramethylcyclopentanone, and the resultant was purified by columnchromatography using a hexane:ethyl acetate (v/v 20:1) solvent, and thenrecrystallized from diethylether to obtain a yellow solid compound. Theyield was 56%.

¹H NMR (C6D6): δ 1.20 (t, J=7.6 Hz, 2H, quin-CH₂), 1.71 (s, 1H, xx),2.29 (s, 2H, quin-CH₂), 2.38 (t, J=6.0 Hz, 2H, quin-CH₂), 2.64 (s, 1H,quin-CH₂), 2.72 (s, 2H, quin-CH₂), 2.30 (s, 1H, N—H), 3.82 (s, 0.5H,N—H), 4.81 (s, 1H, quin-CH), 6.42 (d, J=7.2 Hz, 2H, quin-CH), 6.81 (t,J=7.2 Hz, 1H, quin-CH), 6.94 (dd, J=1.2, 7.2 Hz, 1H, quin-CH), 7.10 (d,J=7.6 Hz, 2H, fluorenyl-CH), 7.23 (t, J=7.2 Hz, 2H, fluorenyl-CH), 7.32(d, J=7.6 Hz, 2H, fluorenyl-CH), 7.42 (d, J=6.8 Hz, 1H, quin-CH), 7.67(d, J=7.2 Hz, 2H, fluorenyl-CH) ppm.

EXAMPLE 6

Preparation of[(1,2,3,4-Tetrahydroquinolin-8-yl)fluorenyl-eta5,kapa-N]titaniumdimethyl (Compound 5c)

A dilithium compound (Compound 4c) was prepared in the same manner asthe preparation method of [Example 2] except that5-fluorenyl-1,2,3,4-tetrahydroquinoline was used instead of8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline.The yield was 94%.

¹H NMR (C6D6): δ 2.17 (s, 2H, quin-CH₂), 3.29-2.26 (m, 2H, quin-CH₂),4.11 (br s, 2H, quin-CH₂), 6.31 (t, J=7.2 Hz, 1H, quin-CH), 6.91 (t,J=7.6 Hz, 2H, fluorenyl-CH), 6.99 (d, J=7.2 Hz, 1H, quin-CH), 7.12 (t,J=6.8 Hz, 2H, fluorenyl-CH), 7.58 (dd, J=1.2, 7.6 Hz, 1H, quin-CH), 8.15(d, J=8.0 Hz, 2H, fluorenyl-CH), 8.57 (d, J=8.0 Hz, 2H, fluorenyl-CH)ppm.

A titanium compound was prepared in the same manner as in [Example 2]using the resulting lithium salt compound (Compound 4c). The yield was47%.

¹H NMR (C6D6): δ 0.14 (s, 6H, Ti—CH₃), 1.56-1.68 (m, 2H, quin-CH₂), 2.48(t, J=6.4 Hz, 2H, quin-CH₂), 4.18-4.30 (m, 2H, quin-CH₂), 6.88-6.96 (m,3H, CH), 7.04 (d, J=7.6 Hz, 1H, quin-CH), 7.10 (ddd, J=1.2, 6.8, 8.4 Hz,2H, fluorenyl-CH), 7.17 (dd, J=0.8, 8.4 Hz, 2H, fluorenyl-CH), 7.28 (d,J=7.2 Hz, 1H, quin-CH), 7.94 (dd, J=0.8, 8.4 Hz, 2H, fluorenyl-CH) ppm.¹³C NMR (C6D6): δ 14.54, 22.76, 27.26, 48.58, 59.65, 111.21, 118.69,118.98 120.17, 123.34, 123.67, 126.16, 126.42, 127.75, 129.29, 129.41,137.28, 160.63 ppm.

EXAMPLE 7 Preparation of7-(2,3,4,5-Tetramethyl-1,3-cyclopentadienyl)indoline (Compound 3d)

The procedure was carried out in the same manner as the preparationmethod of [Example 1] except that indoline was used instead of1,2,3,4-tetrahydroquinoline, and the resultant was purified by columnchromatography using a hexane:ethyl acetate (v/v, 20:1) solvent toobtain a yellow oil. The yield was 15%.

¹H NMR (C6D6): δ 0.99 (d, J=7.6 Hz, 1H, Cp-CH), 1.82 (s, 3H, Cp-CH₃),1.87 (s, 6H, Cp-CH₃, 2.68-2.88 (m, 2H, ind-CH₂), 2.91-2.99 (m, 1H,Cp-CH), 3.07-3.16 (m, 3H, ind-CH₂N—H), 6.83 (t, J=7.4 Hz, 1H, ind-CH),6.97 (d, J=7.6 Hz, 1H, ind-CH), 7.19 (d, J=6.8 Hz, 1H, ind-CH) ppm.

EXAMPLE 8 Preparation of[(Indolin-7-yl)tetramethylcyclopentadienyl-eta5,kapa-N]titanium dimethyl(Compound 5d)

A titanium compound was prepared in the same manner as the preparationmethod of [Example 2] except that7-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)indoline was used instead of8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline.The yield was 71%.

¹H NMR (C6D6): δ 0.69 (s, 6H, Ti—CH₃), 1.71 (s, 6H, Cp-CH₃), 2.04 (s,6H, Cp-CH₃), 2.73 (t, J=8.0 Hz, 2H, ind-CH₂), 4.67 (t, J=8.0 Hz, 2H,ind-CH₂), 6.82 (t, J=7.2 Hz, 1H, ind-CH), 7.00 (t, J=7.2 Hz, 2H, ind-CH)ppm. ¹³C NMR (C6D6): δ 12.06, 12.15, 32.24, 54.98, 56.37, 120.57,120.64, 121.54, 124.02, 126.52, 126.81, 136.75 ppm.

EXAMPLE 9 Preparation of2-methyl-8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline(Compound 3e)

The procedure was carried out in the same manner as the preparationmethod of [Example 1] except that 2-methyl-1,2,3,4-tetrahydroquinoline(5.02 g, 34.1 mmol) was used instead of 1,2,3,4-tetrahydroquinoline. Theyield was 51%.

¹H NMR (CDCl₃): δ 6.89 (d, J=7.2 Hz, 1H, CH), δ 6.74 (d, J=7.2 Hz, 1H,CH), δ 6.57 (t, J=7.4 Hz, 1H, CH), δ 3.76 (br s, 1H, NH), δ 3.45 (br s,1H, Cp-CH), δ 3.32 (m, 1H, quinoline-CH), δ 3.09-2.70 (m, 2H,quinoline-CH), δ 1.91 (s, 3H, Cp-CH₃), δ 1.87 (s, 3H, Cp-CH₃), δ 1.77(s, 3H, Cp-CH₃), δ 1.67-1.50 (m, 2H, quinoline-CH₂), δ 1.17 (d, J=64 Hz,3H, quinoline-CH₃), δ 0.93 (d, J=7.6 Hz, 3H, Cp-CH₃) ppm.

EXAMPLE 10 Preparation of[(2-Methyl-1,2,3,4-tetrahydroquinolin-8-yl)tetramethylcyclopenta-dienyl-eta5,kapa-N]titanium(IV) dimethyl (Compound 5e)

A dilithium salt compound (Compound 4e) (4.92 g, 77%) as a pale yellowsolid, where 1.17 equivalents of diethyl ether were coordinated, wasprepared in the same manner as in [Example 2] except that2-methyl-8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline(4.66 g, 17.4 mmol) was used instead of8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline.

¹H NMR (Pyridine-d8): δ 7.37 (br s, 1H, CH), δ 7.05 (d, J=6 Hz, 1H, CH),δ 6.40 (t, J=6.8 Hz, 1H, CH), δ 3.93 (br s, 1H, CH), δ 3.27 (m, 1H, CH),δ 3.06 (m, 1H, CH), δ 2.28-2.07 (m, 12H, Cp-CH₃), δ 1.99 (m, 1H, CH), δ1.78 (m, 1H, CH), δ 1.18 (d, J=5.6 Hz, quinoline-CH₃) ppm.

A titanium compound (0.56 g, 60%) was prepared in the same manner as in[Example 2] using the resulting dilithium salt compound (Compound 4e)(1.00 g, 2.73 mmol).

¹H NMR (CDCl₃): δ 6.95 (d, J=8 Hz, 1H, CH), δ 6.91 (d, J=8 Hz, 1H, CH),δ 6.73 (t, J=8 Hz, 1H, CH), δ 5.57 (m, 1H, CH), δ 2.83 (m, 1H, CH), δ2.55 (m, 1H, CH), δ 2.24 (s, 3H, Cp-CH₃), δ 2.20 (s, 3H, Cp-CH₃), δ1.94-1.89 (m, 1H, CH), δ 1.83-1.75 (m, 1H, CH), δ 1.70 (s, 3H, Cp-CH₃),δ 1.60 (s, 3H, Cp-CH₃), δ 1.22 (d, J=6.8 Hz, 3H, quinoline-CH₃), δ 0.26(d, J=6.8 Hz, 6H, TiMe₂-CH₃) ppm.

EXAMPLE 11 Preparation of6-methyl-8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline(Compound 3f)

The procedure was carried out in the same manner as the preparationmethod of [Example 1] except that 6-methyl-1,2,3,4-tetrahydroquinoline(5.21 g, 35.4 mmol) was used instead of 1,2,3,4-tetrahydroquinoline. Theyield was 34%.

¹H NMR (CDCl₃): δ 6.70 (s, 1H, CH), δ 6.54 (s, 1H, CH), δ 3.71 (br s,1H, NH), δ 3.25-3.05 (m, 3H, Cp-CH, quinoline-CH₂), δ 2.76 (t, J=6.4 Hz,2H, quinoline-CH₂), δ 2.19 (s, 3H, CH₃), δ 1.93-1.86 (m, 2H,quinoline-CH₂), δ 1.88 (s, 3H, Cp-CH₃), δ 1.84 (s, 3H, Cp-CH₃), δ 1.74(s, 3H, Cp-CH₃), δ 0.94 (br d, J=6.8 Hz, 3H, Cp-CH₃) ppm.

EXAMPLE 12 Preparation of[(6-methyl-1,2,3,4-tetrahydroquinolin-8-yl)tetramethylcyclopenta-dienyl-eta5,kapa-N]titaniumdimethyl (Compound 5f)

A dilithium salt compound (Compound 4f) (2.56 g, 58%) as a pale yellowsolid, where 1.15 equivalents of diethyl ether were coordinated, wasprepared in the same manner as in [Example 2] except that6-methyl-8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline(3.23 g, 12.1 mmol) was used instead of8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline.

¹H NMR (Pyridine-d8): δ 7.02 (br s, 1H, CH), δ 6.81 (s, 1H, CH), δ 3.94(m, 2H, CH₂), δ 3.19 (m, 2H, CH₂), δ 2.52-2.10 (m, 17H, CH₂,quinoline-CH₃, Cp-CH₃) ppm.

A titanium compound (0.817 g, 58%) was prepared in the same manner as in[Example 2] using the resulting dilithium salt compound (Compound 4f)(1.50 g, 4.12 mmol).

¹H NMR (C₆D₆): δ 6.87 (s, 1H, CH), δ 6.72 (s, 1H, CH), δ 4.57 (m, 2H,CH₂), δ 2.45 (t, J=6.2 Hz, 2H, CH₂), δ 2.24 (s, 3H, quinoline-CH₃), δ2.05 (s, 6H, Cp-CH₃), δ 1.72-1.66 (m, 2H, CH₂), δ 1.69 (s, 6H, Cp-CH₃),δ 0.57 (s, 6H, TiMe₂-CH₃) ppm.

EXAMPLE 13 Preparation of2-methyl-7-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)indoline (Compound3g)

The procedure was carried out in the same manner as in [Example 1]except that 2-methylindoline (6.23 g, 46.8 mmol) was used instead of1,2,3,4-tetrahydroquinoline. The yield was 19%.

¹H NMR (CDCl₃): δ 6.97 (d, J=7.2 Hz, 1H, CH), δ 6.78 (d, J=8 Hz, 1H,CH), δ 6.67 (t, J=7.4 Hz, 1H, CH), δ 3.94 (m, 1H, quinoline-CH), δ 3.51(br s, 1H, NH), δ 3.24-3.08 (m, 2H, quinoline-CH₂, Cp-CH), δ 2.65 (m,1H, quinoline-CH₂), δ 1.89 (s, 3H, Cp-CH₃), δ 1.84 (s, 3H, Cp-CH₃), δ1.82 (s, 3H, Cp-CH₃), δ 1.13 (d, J=6 Hz, 3H, quinoline-CH₃), δ 0.93 (3H,Cp-CH₃) ppm.

EXAMPLE 14 Preparation of[(2-methylindolin-7-yl)tetramethylcyclopentadienyl-eta5,kapa-N]titaniumdimethyl (Compound 5g)

A dilithium salt compound (Compound 4g) (1.37 g, 50%), where 0.58equivalent of diethyl ether was coordinated, was prepared in the samemanner as in [Example 2] except that2-methyl-7-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-indoline (2.25 g,8.88 mmol) was used instead of8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline.

¹H NMR (Pyridine-d8): δ 7.22 (br s, 1H, CH), δ 7.18 (d, J=6 Hz, 1H, CH),δ 6.32 (t, 1H, CH), δ 4.61 (br s, 1H, CH), δ 3.54 (m, 1H, CH), δ 3.00(m, 1H, CH), δ 2.35-2.12 (m, 13H, CH, Cp-CH₃), δ 1.39 (d, indoline-CH₃)ppm.

A titanium compound was prepared in the same manner as in [Example 2]using the resulting dilithium salt compound (Compound 4g) (1.37 g, 4.44mmol).

¹H NMR (C₆D₆): δ 7.01-6.96 (m, 2H, CH), δ 6.82 (t, J=7.4 Hz, 1H, CH), δ4.96 (m, 1H, CH), δ 2.88 (m, 1H, CH), δ 2.40 (m, 1H, CH), δ 2.02 (s, 3H,Cp-CH₃), δ 2.01 (s, 3H, Cp-CH₃), δ 1.70 (s, 3H, Cp-CH₃), δ 1.69 (s, 3H,Cp-CH₃), δ 1.65 (d, J=64 Hz, 3H, indoline-CH₃), δ 0.71 (d, J=10 Hz, 6H,TiMe₂-CH₃) ppm.

EXAMPLE 15

Preparation ofN,N′-1-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)phenylethylamine(Compound 3h)

The procedure was carried out in the same manner as in [Example 1]except that 2-methylindoline (6.23 g, 46.8 mmol) was used instead of1,2,3,4-tetrahydroquinoline. Column chromatography using a hexane:ethylacetate (v/v 20:1) solvent was performed to obtain a yellow oil. Theyield was 45%.

¹H NMR (C6D6): δ 0.88 (t, J=6.4 Hz, 3H, Et-CH₃), 0.99 (d, J=7.7 Hz, 3H,Cp-CH₃), 1.77 (s, 3H, Cp-CH₃), 1.79 (s, 3H, Cp-CH₃), 1.83 (s, 3H,Cp-CH₃), 2.79-2.94 (m, 2H, Et-CH₂), 3.05 (br m, 1H, Cp-CH), 3.74 (br m,1H, N—H), 6.66 (d, J=8.0 Hz, 1H, Ph-H), 6.84 (t, J=7.2 Hz, 1H, Ph-H),7.07 (dd, J=1.2 7.2 Hz, 1H, Ph-H), 7.25 (t, J=7.2 Hz, 1H, Ph-H) ppm.

EXAMPLE 16

Preparation of[Phenylene(tetramethylcyclopentadienyl)(ethylamido)]titanium dimethyl(Compound 5h)

A dilithium salt compound (Compound 4f) as a pale yellow solid, where0.58 equivalent of diethyl ether was coordinated, was prepared in thesame manner as in [Example 2] except thatN,N′-1-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)phenylethylamine wasused instead of8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline.The yield was 82%.

¹H NMR (C6D6, C5D5N): δ 1.25 (br s, 3H, Et-CH₃), 2.03 (br s, 6H,Cp-CH₃), 2.18 (br s, 6H, Cp-CH₃), 3.43 (br s, 2H, Et-CH₂), 6.40 (br s,1H, Ph-H), 6.65 (br s, 1H, Ph-H), 7.27 (br s, 1H, Ph-H), 7.53 (br s, 1H,Ph-H) ppm. ¹³C NMR (C6D6, C5D5N): δ 11.63, 12.16, 18.90, 45.15, 104.50,105.82, 106.41, 131.28, 163.39 ppm.

A titanium compound was prepared in the same manner as in [Example 2]using the resulting dilithium salt compound (Compound 4h). The yield was66%.

¹H NMR (C6D6): δ 0.56 (s, 6H, Ti—CH₃), 1.20 (t, J=7.2 Hz, 3H, Et-CH₃),1.58 (s, 6H, Cp-CH₃), 2.03 (s, 6H, Cp-CH₃), 4.48 (q, J=7.2 Hz, 2H,Et-CH₂), 6.27 (d, J=8.0 Hz, 1H, Ph-H), 6.88 (t, J=7.2 Hz, 1H, Ph-H),7.12 (d, J=7.2 Hz, 1H, Ph-H), 7.20 (t, J=7.2 Hz, 1H, Ph-H) ppm. ¹³C NMR(C6D6): δ 12.03, 12.09, 14.14, 41.29, 50.89, 108.60, 119.82, 121.12,128.70, 129.27, 136.08, 163.40 ppm.

EXAMPLE 17 Preparation ofN,N′-1-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)phenyl-iso-propylamine(Compound 3i)

The procedure was carried out in the same manner as in [Example 1]except that 2-methylindoline (6.23 g, 46.8 mmol) was used instead of1,2,3,4-tetrahydroquinoline. Colman chromatography using ahexane:toluene (v/v 2:1) solvent was performed to obtain a yellow oil.The yield was 16%.

¹H NMR (C6D6): δ 0.91 (d, J=6.0 Hz, 2H, Cp-CH₃), 0.94-1.05 (m, 6H,iPr-CH₃), 1.76 (s, 3H, Cp-CH₃), 1.80 (s, 3H, Cp-CH₃), 1.82 (s, 3H,Cp-CH₃), 3.02 (br m, 1H, Cp-CH), 3.37-3.50 (m, 1H, iPr-CH), 3.74 (br s,1H, N—H), 6.66 (d, J=8.0 Hz, 1H, Ph-CH), 6.81 (t, J=7.2 Hz, 1H, Ph-CH),7.06 (dd, J=1.6 7.2 Hz, 1H, Ph-CH), 7.23 (t, J=7.2 Hz, 1H, Ph-CH) ppm.

EXAMPLE 18 Preparation of[Phenylene(tetramethylcyclopentadienyl)(iso-propylamido)]titaniumdimethyl (Compound 5i)

A dilithium salt compound (Compound 4i) was prepared in the same manneras in [Example 2] except thatN,N′-1-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)phenyl-iso-propylamine)was used instead of8-(2,3,4,5-tetramethyl-1,3-cyclopentadienyl)-1,2,3,4-tetrahydroquinoline.The yield was 87%.

¹H NMR (C6D6, C5D5N): δ 1.21 (br s, 6H, iPr-CH₃), 1.89 (br s, 6H,Cp-CH₃), 2.14 (br s, 6H, Cp-CH₃), 3.84 (br s, 1H, iPr-CH), 6.34 (br s,1H, Ph-CH), 6.68 (br s, 1H, Ph-CH), 7.21-7.57 (br m, 2H, Ph-CH) ppm. ¹³CNMR (C6D6, C5D5N): δ 11.49, 12.11, 26.06, 47.54, 103.81, 106.55, 108.42,131.60, 162.49 ppm.

A titanium compound was prepared in the same manner as in [Example 2]using the resulting dilithium salt compound (Compound 4i). The yield was77%.

COMPARATIVE EXAMPLE 1 Preparation ofdimethylsilyl(t-butylamido)(tetramethylcyclopentadienyl)titaniumdichloride (Compound 33)

A dimethylsilyl(t-butylamido)(tetramethylcyclopentadienyl)titaniumdichloride transition metal complex was purchased from BoulderScientific, Inc. (U.S.A.), and directly used for the ethylenecopolymerization.

Ethylene Copolymerization

EXAMPLE 19 Copolymerization of High-Pressure Ethylene and 1-butene

A hexane solvent (1.0 L) and an appropriate amount of 1-butenecomonomers were charged into a 2 L autoclave reactor. The reactor washeated to 150° C. that was a polymerization temperature, and was filledwith about 35 bar of ethylene. The titanium transition metal complex(1.0 μmol, Al/Ti=25) (Compound 5a) treated with an appropriate amount ofa triisobutylaluminum compound and adimethylaniliniumtetrakis(pentafluorophenyl)borate cocatalyst solution(B/Ti=5) were added to a catalyst injecting cylinder, and then injectedinto the reactor. Polymerization was performed for 10 minutes bycontinuously injecting ethylene in order to maintain the pressure in thereactor between 34 bar to 35 bar. Heat generated from the reaction wasremoved through a cooling coil installed in the reactor, and thetemperature was maintained as constant as possible. After thepolymerization, the polymer solution was discharged to the lower portionof the reactor, and cooled using excess ethanol. The obtained polymerwas dried for over 12 hours or more in a vacuum oven. The experimentresults are shown in Table 1.

EXAMPLE 20 to EXAMPLE 28 Copolymerization of High-Pressure Ethylene and1-butene

Copolymerization was performed in the same manner as in [Example 19]except that the transition metal complexes (Compound 5b, 5c, 5d, 5e, 5f,5g, 5h, and 5i) as prepared in the above Examples were used instead ofthe transition metal complex, Compound 5a, as prepared in [Example 2].However, in Example 28, the polymerization temperature was 120° C. Theexperiment results are shown in Table 1.

COMPARATIVE EXAMPLE 2 TO COMPARATIVE EXAMPLE 3 Copolymerization ofHigh-Pressure Ethylene and 1-butene

Copolymerization was performed in the same manner as in [Example 19]except that the transition metal complex (Compound 33) as obtained in[Comparative Example 1] was used instead of Compound 5a as prepared in[Example 2]. However, in Comparative Example 3, the polymerizationtemperature was 120° C. The experiment results are shown in Table 1.

Evaluation on Properties (Weight, Activity, Melt Index, Melting Point,and Density)

A melt index (MI) of a polymer was measured in accordance with ASTMD-1238 (Conditions: E, 190° C., 2.16 Kg load). A melting point (Tm) of apolymer was measured using a Differential Scanning Calorimeter (DSC)2920 manufactured by TA Inc. That is, the temperature was increased to200° C., maintained at 200° C. for 5 minutes, and decreased to 30° C.Then, the temperature was increased again, and the summit of the DSCcurve was measured as the melting point. Here, the temperature wasincreased and decreased by 10° C./min, and the melting point wasobtained in a second temperature increase period.

In order to measure the density of a polymer, a sample that had beentreated with an antioxidant (1,000 ppm) was formed into a sheet having athickness of 3 mm and a radius of 2 orn by a 180° C. press mold, andthen the prepared sheet was cooled by 10° C./min. The cooled sheet wasmeasured using a mettler scale.

The various properties of the copolymers obtained in Examples 19 to 28,and Comparative Examples 2 and 3 were measured, and the results areshown in Table 1.

TABLE 1 Results of copolymerization of ethylene and 1-butene Transitionmetal Melt Melt complexes 1-Butene Activity index^(a) index^(b) DensityExample used (M) (kg/mmol-Ti) (g/10 min) (g/10 min) (g/cc) Example 19Compound 5a 1.6 43.7 3.5 28.8 0.859 Example 20 Compound 5b 1.6 3.4 0 00.870 Example 21 Compound 5c 1.6 16.6 0 0 0.860 Example 22 Compound 5d1.6 15.3 0 0.66 0.873 Example 23 Compound 5e 1.6 36.0 15.4 — 0.862Example 24 Compound 5f 1.6 29.8 1.3 12.5 0.860 Example 25 Compound 5g1.6 22.1 0 0.8 0.873 Example 26 Compound 5h 1.6 22.0 1.4 15.8 0.866Example 27 Compound 5i 1.6 8.5 0 0 0.876 Comparative Compound 33 1.630.5 5.9 59 0.900 Example 2 Example 28 Compound 5a^(c) 1.2 57.5 0 1.30.881 Comparative Compound 33^(c) 1.2 44.1 0 1.2 0.902 Example 3 ^(a)I₂value, ^(b)I_(21.6) value, ^(C)Polymerization at 120° C.

As shown in Table 1, most of the transition metal complexes of Examplesaccording to the present invention provided copolymers having relativelyhigher molecular weights and lower densities, as compared with those ofComparative Examples, when 1-butene and ethylene was copolymerized.

Accordingly, it is confirmed that the transition metal complexesaccording to the present invention have relatively excellent reactivityfor olefin monomers having large steric hindrance such as 1-butene.

Particularly, the transition metal complexes (Compounds 5a, 5e, and 5f)used in Example 19, 23, and 24 showed equal or higher catalyst activity,as compared to the transition metal complex (Compound 33) used inComparative Examples. Further, in the polymerization at 120° C., thetransition metal complexes (Compounds 5a, 5e, and 51) used in Examples19, 23, and 24 showed higher catalyst activity, and the obtainedcopolymers had higher molecular weights and lower densities, as comparedto the transition metal complex (Compound 33) used in ComparativeExamples.

1. A method for preparing a transition metal complex, comprising thesteps of: (a) reacting an amine-based compound represented by Formula 1below with an alkyl lithium, and then adding a compound containing aprotecting group (-R₀) thereto to prepare a compound represented byFormula 2 below; (b) reacting the compound represented by Formula 2 withan alkyl lithium, and adding a ketone-based compound represented byFormula 3 below to prepare an amine-based compound represented byFormula 4 below; (c) reacting the compound represented by Formula 4 withn-butyl lithium to prepare a dilithium compound represented by Formula 5below; and (d) reacting the compound represented by Formula 5 with MCl₄(M=Ti, Zr, or Hf) and an organic lithium compound to prepare atransition metal complex represented by Formula 6 below:

wherein R₀ is a protecting group; R₁, R₂, R₃, and R₄ are eachindependently a hydrogen atom; a silyl radical; an alkyl radical having1 to 20 carbon atoms or an aryl radical having 5 to 20 carbon atoms; analkenyl radical having 2 to 20 carbon atoms, an alkylaryl radical having6 to 20 carbon atoms, or an arylalkyl radical having 6 to 20 carbonatoms; or a metalloid radical of a metal belonging to Group 14substituted with a hydrocarbyl having 1 to 20 carbon atoms; at least twoof R₁, R₂, R₃, and R₄ may be connected to each other to form analiphatic ring having 5 to 20 carbon atoms or an aromatic ring having 5to 20 carbon atoms; at least two of R₁, R₂, R₃, and R₄ may be connectedto each other by an alkylidine radical having 1 to 20 carbon atoms,containing an alkyl radical having 1 to 20 carbon atoms or an arylradical having 5 to 20 carbon atoms to form a ring; R₅, R₆, R₇, and R₈are each independently a hydrogen atom; a halogen radical; or an alkylradical having 1 to 20 carbon atoms or an aryl radical having 5 to 20carbon atoms; and at least two of R₅, R₆, R₇, and R₈ may be connected toeach other to form an aliphatic ring having 5 to 20 carbon atoms or anaromatic ring having 5 to 20 carbon atoms; R₉ is a hydrogen atom; abranched or linear alkyl radical having 1 to 20 carbon atoms; or an arylradical having 5 to 20 carbon atoms; M is a transition metal belongingto Group 4; and Q₁ and Q₂ are each independently a halogen radical; analkylamido radical having 1 to 20 carbon atoms, or an arylamido radicalhaving 5 to 20 carbon atoms; an alkyl radical having 1 to 20 carbonatoms, an alkenyl radical having 2 to 20 carbon atoms, an aryl radicalhaving 5 to 20 carbon atoms, an alkylaryl radical having 6 to 20 carbonatoms, or an arylalkyl radical having 6 to 20 carbon atoms; or analkylidene radical having 1 to 20 carbon atoms.
 2. The method forpreparing a transition metal complex according to claim 1, wherein thecompound containing a protecting group is a compound selected from thegroup consisting of trimethylsilyl chloride, benzyl chloride,t-butoxycarbonyl chloride, benzyloxycarbonyl chloride, and carbondioxide.
 3. The method for preparing a transition metal complexaccording to claim 1, wherein when the compound containing a protectinggroup is carbon dioxide, the compound represented by Formula 2 is alithium carbamate compound represented by Formula 2a below:

wherein R₅, R₆, R₇, R₈, R₉, and R₁₀ are as defined in claim
 1. 4. Themethod for preparing a transition metal complex according to claim 1,wherein the transition metal complex represented by Formula 6 isrepresented by Formula 9 below:

wherein R₁₁, R₁₂, R₁₃, and R₁₄ are each independently a hydrogen atom;an alkyl radical having 1 to 20 carbon atoms or an aryl radical having 5to 20 carbon atoms; an alkenyl radical having 2 to 20 carbon atoms, analkylaryl radical having 6 to 20 carbon atoms, or an arylalkyl radicalhaving 6 to 20 carbon atoms; or a metalloid radical of a metal belongingto Group 14 substituted with hydrocarbyl having 1 to 20 carbon atoms;and at least two of R₁₁, R₁₂, R₁₃, and R₁₄ may be connected to eachother to form an aliphatic ring having 5 to 20 carbon atoms or anaromatic ring having 5 to 20 carbon atoms; R₁₅, R₁₆, R₁₇, and R₁₈ areeach independently a hydrogen atom; a halogen radical; an alkyl radicalhaving 1 to 20 carbon atoms or an aryl radical having 5 to 20 carbonatoms; and at least two of R₁₅, R₁₆, R₁₇, and R₁₈ may be connected toeach other to form an aliphatic ring having 5 to 20 carbon atoms or anaromatic ring having 5 to 20 carbon atoms; R₂₁ is a hydrogen atom; abranched, linear, or cyclic alkyl radical having 1 to 20 carbon atoms;or an aryl radical having 5 to 20 carbon atoms; M is a transition metalbelonging to Group 4; and Q₃ and Q₄ are each independently a halogenradical; an alkylamido radical having 1 to 20 carbon atoms or anarylamido radical having 5 to 20 carbon atoms; or an alkyl radicalhaving 1 to 20 carbon atoms.
 5. The method for preparing a transitionmetal complex according to claim 1, wherein the transition metal complexrepresented by Formula 6 is represented by one of the structuralformulae as shown below:


6. A transition metal complex represented by Formula 6 below:

wherein R₁, R₂, R₃, and R₄ are each independently a hydrogen atom; asilyl radical; an alkyl radical having 1 to 20 carbon atoms or an arylradical having 5 to 20 carbon atoms; an alkenyl radical having 2 to 20carbon atoms, an alkylaryl radical having 6 to 20 carbon atoms, or anarylalkyl radical having 6 to 20 carbon atoms; or a metalloid radical ofa metal belonging to Group 14 substituted with hydrocarbyl having 1 to20 carbon atoms; at least two of R₁, R₂, R₃, and R₄ may be connected toeach other to form an aliphatic ring having 5 to 20 carbon atoms or anaromatic ring having 5 to 20 carbon atoms; and at least two of R₁, R₂,R₃, and R₄ may be connected to each other by an alkylidine radicalhaving 1 to 20 carbon atoms, containing an alkyl radical having 1 to 20carbon atoms or an aryl radical having 5 to 20 carbon atoms to form aring; R₅, R₆, R₇, and R₈ are each independently a hydrogen atom; ahalogen radical; an alkyl radical having 1 to 20 carbon atoms or an arylradical having 5 to 20 carbon atoms; and at least two of R₅, R₆, R₇ andR₈ may be connected to each other to form an aliphatic ring having 5 to20 carbon atoms or an aromatic ring having 5 to 20 carbon atoms; R₉ is ahydrogen atom; a branched or linear alkyl radical having 1 to 20 carbonatoms; or an aryl radical having 5 to 20 carbon atoms; M is a transitionmetal belonging to Group 4; and Q₁ and Q₂ are each independently ahalogen radical; an alkylamido radical having 1 to 20 carbon atoms, oran arylamido radical having 5 to 20 carbon atoms; an alkyl radicalhaving 1 to 20 carbon atoms, an alkenyl radical having 2 to 20 carbonatoms, an aryl radical having 5 to 20 carbon atoms, an alkylaryl radicalhaving 6 to 20 carbon atoms, or an arylalkyl radical having 6 to 20carbon atoms; or an alkylidene radical having 1 to 20 carbon atoms. 7.The transition metal complex according to claim 6, wherein thetransition metal complex is represented by Formula 9 below:

wherein R₁₁, R₁₂, R₁₃, and R₁₄ are each independently a hydrogen atom; asilyl radical; an alkyl radical having 1 to 20 carbon atoms or an arylradical having 5 to 20 carbon atoms; an alkenyl radical having 2 to 20carbon atoms, an alkylaryl radical having 6 to 20 carbon atoms, or anarylalkyl radical having 6 to 20 carbon atoms; or a metalloid radical ofa metal belonging to Group 14 substituted with hydrocarbyl having 1 to20 carbon atoms; and at least two of R₁₁, R₁₂, R₁₃, and R₁₄ may beconnected to each other to form an aliphatic ring having 5 to 20 carbonatoms or an aromatic ring having 5 to 20 carbon atoms; R₁₅, R₁₆, R₁₇,and R₁₈ are each independently a hydrogen atom; a halogen radical; analkyl radical having 1 to 20 carbon atoms or an aryl radical having 5 to20 carbon atoms; and at least two of R₁₅, R₁₆, R₁₇, and R₁₈ may beconnected to each other to form an aliphatic ring having 5 to 20 carbonatoms or an aromatic ring having 5 to 20 carbon atoms; R₂₁ is a hydrogenatom; a branched, linear, or cyclic alkyl radical having 1 to 20 carbonatoms; or an aryl radical having 5 to 20 carbon atoms; M is a transitionmetal belonging to Group 4; and Q₃ and Q₄ are each independently ahalogen radical; an alkylamido radical having 1 to 20 carbon atoms or anarylamido radical having 5 to 20 carbon atoms; or an alkyl radicalhaving 1 to 20 carbon atoms.
 8. The transition metal complex accordingto claim 6, wherein the transition metal complex is represented by oneof the structural formulae as shown below:


9. An amine-based compound represented by Formula 4 below:

wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, and R₉ are as defined inclaim
 1. 10. A catalyst composition comprising: a transition metalcomplex represented by Formula 6 below; and at least one cocatalystcompound selected from the group consisting of the compounds representedby Formulae 10, 11, and 12 below:

wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, Q₁, and Q₂ are as defined inclaim 1;—[Al(R₂₂)—O]_(a)—  <Formula 10> wherein R₂₂'s are each independently ahalogen radical; a hydrocarbyl radical having 1 to 20 carbon atoms; or ahydrocarbyl radical having 1 to 20 carbon atoms substituted withhalogen; and a is an integer of no less than 2;D(R₂₂)₃  <Formula 11> wherein D is aluminum or boron; and R₂₂'s are eachindependently as defined above;[L-H]⁺[Z(A)₄]⁻ or [L]⁺[Z(A)₄]⁻  <Formula 12> wherein L is a neutral orcationic Lewis acid; H is a hydrogen atom; Z is an element belonging toGroup 13; A's are each independently an aryl radial having 6 to 20carbon atoms or alkyl radical having 1 to 20 carbon atoms, substitutedwith one or more hydrogen atoms; and the substituent is a halogen, ahydrocarbyl radical having 1 to 20 carbon atoms, an alkoxy radicalhaving 1 to 20 carbon atoms, or an aryloxy radical having 6 to 20 carbonatoms.
 11. The catalyst composition according to claim 10, wherein thetransition metal complex represented by Formula 6 is represented byFormula 9 below:

wherein R₁₁, R₁₂, R₁₃, R₁₄, R₁₅, R₁₆, R₁₇, R₁₈, R₁₉, R₂₀, R₂₁, Q₃, andQ₄ are as defined in claim
 7. 12. The catalyst composition according toclaim 10, wherein the transition metal complex represented by Formula 6is represented by one of the structural formulae as shown below:.


13. The catalyst composition according to claim 10, wherein the molarratio of the transition metal complex represented by Formula 6 to thecompound represented by Formula 10 or 11 is 1:2 to 1:5000, and the molarratio of the transition metal complex represented by Formula 6 to thecompound represented by Formula 12 is 1:1 to 1:25.